Kerbodyne SSTO Division: Omnibus Thread

[Wanderfound]

My crappy work computer hates photobucket so I can't open the album, can you actually land the Farlander on Duna? It looks like it doesn't have enough wing at first glance.

The flight test album doesn't go beyond LKO, but flying on Duna really doesn't require any more wing than Kerbin; Duna sea level is equivalent to moderate altitude Kerbin, and if you can fly in one you can fly in the other.

More wing will allow you to land more slowly, but not by all that much, and increases the chance of a wingtip groundstrike during landing. As demonstrated in my Interplanetary Spaceplanery series (on Youtube), the key to spaceplaning on Duna is mostly about maintaining control during post-touchdown braking.

A sufficently good pilot could land most things there, but to make it easier you want highly stable wide-set landing gear, a hint of VTOL thrust to soften the touchdown (and to reduce the AoA required for level flight immediately pre-touchdown), and some retrothrust to enhance braking. The Farlander has most of that already, but you might want to add some tailstrike guards to protect the nuke during an overly bouncy landing.

It's also worth remembering that the tailplane and canards are wings in their own right. Spreading the lifting duties over the three surfaces reduces the amount of primary wing area required.

[WhiteKnuckle]

The flight test album doesn't go beyond LKO, but flying on Duna really doesn't require any more wing than Kerbin; Duna sea level is equivalent to moderate altitude Kerbin, and if you can fly in one you can fly in the other.

Yeah my problem has never been flying on Duna, it's been getting to a reasonable speed for landing.

I actually managed my first landing just a few days ago, thanks in part to some of the stuff you showed off in the youtube series:

The absurd levels of diheadral on the wings was actually a concesion to the lauch vehicle I used, but I found that it, combined with the wing mounted landing gear made it possible to bounce from dune to dune with hilarious ease... of course I should have just picked a better landing site. The other thing that really saved me was having the forward facing engines on the nacelles for braking thrust.

[Voculus]

Kerbodyne Farlander

I like this one!

[Wanderfound]

Kerbodyne Harpoon. Fast, fun and useful.

Flight test at http://s1378.photobucket.com/user/craigmotbey/Kerbal/Beta/Kerbodyne%20Showroom/Harpoon/story

Alternate format at http://s1378.photobucket.com/user/craigmotbey/slideshow/Kerbal/Beta/Kerbodyne%20Showroom/Harpoon

Craft file at https://www.dropbox.com/s/saznws5n3diahlm/Kerbodyne%20Harpoon.craft?dl=0

[trawum]

What mod do you use for the FAR data HUD?

[Wanderfound]

What mod do you use for the FAR data HUD?

Kerbal Flight Data​.

[Nowater]

Woaaah, no new plane...

[Wanderfound]

Here y'go...

An update of the classic: Kerbodyne Dementia Nova.

We accept no responsibility for the consequences of incautious use of the main engine at low altitude.

Flight demonstration at http://s1378.photobucket.com/user/craigmotbey/Kerbal/Beta/Kerbodyne%20Showroom/Dementia%20Nova/story

Alternate format at http://s1378.photobucket.com/user/craigmotbey/slideshow/Kerbal/Beta/Kerbodyne%20Showroom/Dementia%20Nova

Craft file at https://www.dropbox.com/s/axe5dwqc8xim5cd/Kerbodyne%20Dementia%20Nova.craft?dl=0

[blowfish]

6g on rocket thrust? Isn't that a bit ... insane? Couldn't you get more delta v out of a smaller engine?

[UnusualAttitude]

Well, no point in using the Mainsail, as the KR-2L has a MegaNewton more thrust, better ISP in vacuum, and weighs only half a tonne more. Might as well go the whole hog. Love it!

[Wanderfound]

6g on rocket thrust? Isn't that a bit ... insane? Couldn't you get more delta v out of a smaller engine?

You did see the name of it, right?

[blowfish]

You did see the name of it, right?

Well yeah but still ... there's insanity and then there's insanity.

[Wanderfound]

Kerbodyne Astrotrout. Orbit and back without any fuss.

Flight test at http://s1378.photobucket.com/user/craigmotbey/Kerbal/Beta/Kerbodyne%20Showroom/Astrotrout/story

Alternate format at http://s1378.photobucket.com/user/craigmotbey/slideshow/Kerbal/Beta/Kerbodyne%20Showroom/Astrotrout

Craft file at https://www.dropbox.com/s/ogjyiwcjnpi4439/Kerbodyne%20Astrotrout.craft?dl=0

[eddiew]

Kerbodyne Astrotrout. Orbit and back without any fuss.

I want you to know Wander, this sort of madness is totally to blame for my new

'spaceplanes'...

Space Seal (left) is KW Rocketry and B9, cos I really needed an MK3 equivalent cargo bay for some physically huge science packages that need to get to Duna orbit. It doesn't actually have wings once the boosters detach, so I'm not really sure if it's a plane... but it does ascend at about 40 degrees, so maybe? The 'Thor' boosters give it about 2900 delta-v so it's a bit of a squeaky-bum moment trying to round out the orbit on a pair of nukes and 0.2 TWR

The Flying Fish has a 2.5m SXT cargo bay to hold a Station Science package that needed at least 3 kerbals to run it, and falls into the 'I did not expect that to work' category. Got to orbit with ~900 delta-v left. With a top up, it might well be Mun capable, and certainly Minmus

Edited March 2, 2015 by eddiew

[Wanderfound]

Tried landing 'em yet? The Seal looks like it might be challenging to get down intact...

[Wanderfound]

Success or excess? Kerbodyne V-Storm.

Flight demo at http://s1378.photobucket.com/user/craigmotbey/Kerbal/Beta/Kerbodyne%20Showroom/V-Storm/story

Alternate format at http://s1378.photobucket.com/user/craigmotbey/slideshow/Kerbal/Beta/Kerbodyne%20Showroom/V-Storm

Craft file at https://www.dropbox.com/s/3f6ind3rfwtdj4m/Kerbodyne%20V-Storm.craft?dl=0

[eddiew]

Tried landing 'em yet? The Seal looks like it might be challenging to get down intact...

Actually they both do fine Seal is stuffed with parachutes and both ends, and has heavy landing gear on the underside. The big boosters are expendable (7400 roots each), similar to your Javelin and Trout planes, so it's a lot less cumbersome on the way down. If there's fuel left you might have to shunt it back or forward to balance it, but it passed a trial run without any problems. It's only problem is that it's very streamlined and doesn't want to slow down.

Flying Fish wobbles because it wants to come down nose first, but the chutes keep it upright and the lift from the winglets is negligible once you're at touchdown speeds. Maiden voyage dropped right onto the runway for style points. Totally my new favourite way to get 3 kerbals to LKO ^^

- - - Updated - - -

Success or excess? Kerbodyne V-Storm.

Perfection :> It's nice to have an SSTO for when you just can't be bothered taking 15 minutes to reach orbit.

[Wanderfound]

A thin-atmosphere no-oxygen rough-landing specialist: Kerbodyne Dunaflyer. Just the thing for your first Duna flight.

Flight demo at http://s1378.photobucket.com/user/craigmotbey/Kerbal/Beta/Kerbodyne%20Showroom/Dunaflyer/story

Alternate format at http://s1378.photobucket.com/user/craigmotbey/slideshow/Kerbal/Beta/Kerbodyne%20Showroom/Dunaflyer

Craft file at https://www.dropbox.com/s/7m1av8dmgf5o32x/Kerbodyne%20Dunaflyer.craft?dl=0

[eddiew]

A thin-atmosphere no-oxygen rough-landing specialist: Kerbodyne Dunaflyer. Just the thing for your first Duna flight.

It does amuse me that tiny things often do better than big lumbering contraptions. Love a minimal ship

If you're up for solving a mystery, Wanderfound (and any interested persons lurking this thread)...

No, really... After many fiddles, I couldn't cure the red numbers in FAR, so I took it up manually with nothing but SAS. This bird hangs at any AoA I point it at, didn't roll, didn't yaw, didn't bend. Very slight nose-up tendency past 25km, but that actually worked well because she got out of the atmosphere fast after passing 30km and ended up in 100x60km by following prograde. For once I placed the engines and intakes one at a time, and good lord the on-air altitude shot up after I did. From a pilot's perspective, this thing is now the best in my fleet!

Unfortunately I was a bit drunk when I built the initial airframe, and I'm confused as to why it works at all Unless it's got a surprise for me when I bring it back down?

Oh, and, yes it was inspired by the Kerbodyne Stratos. I think I'm in love with forward-swept wings They need some planning but... this!

[Wanderfound]

Well, the red showing is all in the "pitch up" and "not enough lift" areas. Not surprising; most things show some red at 30,000m unless they're very light or have a lot of wing.

But by the time you hit 30km, you're probably on a ballistic trajectory (i.e. not really "flying": your wings aren't holding you up) anyway, which makes the "not enough wing" stuff irrelevant. And, as you noticed, a bit of pitch up at altitude can be quite helpful during ascent (albeit potentially lethal during reentry...).

You've got plenty of vertical stabiliser, plenty of horizontal stabiliser, and adequate wing area. That's three of the main issues sorted.

What do the numbers look like at 25km/Mach4? That's where I usually focus my efforts in the SPH.

[eddiew]

What do the numbers look like at 25km/Mach4? That's where I usually focus my efforts in the SPH.

Actually a lot better since I slept on the problem. I woke up realising I hadn't checked that the engines were in line with the CoM - and indeed there was 80kN of torque there, which is where that pitch-up was probably coming from Now much reduced with the magic of offset, and three numbers immediately went green. The only thing I was left with was Mw, which after some tweaking could just barely be persuaded into the negative...

The weak point tends to be Lr/roll, but I don't want to spoil the aesthetics by adding any more upsweep, and if I incline the tail anymore the yaw goes to pot.

All the numbers improve notably as the fuel drains, to the tune of [email protected], but with the canards shunted back I'm not quite sure it can lift off any more and didn't have time to test it before work A previous dry flight run suggested it's sluggish to turn at low altitudes due to the nose not pulling up into the roll. Happily, procedural control surfaces mean I can expand those rear elevons easily, which may ironically let the canards slide forward again. And as ever for one of mine, it's packed with enough chutes to make an emergency landing on the rough anyway - although about one in two of my runway landings now don't explode

Another couple of test cycles and I think it'll be production ready (I seriously spend more time in the SPH than I do 'playing the game' )

[Wanderfound]

How does it come out if you turn those dihedral wingtips into vertical fins (winglets)? It might allow a bit more tailfin dihedral.

[eddiew]

How does it come out if you turn those dihedral wingtips into vertical fins (winglets)? It might allow a bit more tailfin dihedral.

I'll try it when I get home tonight, but my first thought is; ugly Unless I had a fin up and a fin down on each tip... that might look kinda cool.

I'm not too worried though - one of the stats has to be the weak point I guess, and yesterday's model already flew comfortably. Really I'm just nitpicking and trying to optimise the airframe within the bounds of not making major visual changes.

[eddiew]

Wow... woooow did I just learn a big lesson Did some manoeuvre tests both full and empty and couldn't get the Arbalest to turn over all all... like, this plane has practically zero roll control. I think what it does have is from the reaction wheel, not the surfaces.

Anyway, after a while, I figured it out. That cool and excitingly sharp angle at the back of the Arbalest's wings where the control surfaces are? That completely ruins roll. I'm not sure why, but the surfaces just didn't have any effect at any angle of deflection. Thing still went up to orbit beautifully and easily, so I never thought to check whether it could do basic things like turn at sea level Not sure if I should have expected the behaviour I got, or whether FAR just doesn't understand wings on a sharp forward sweep...

So, bit of a rework; reduced the rear angle of the wings, cut back the deflection on the canards so they don't 100% stall anymore, balanced the rear/mid control surfaces so they don't send it into a tumble when the spoilers are deployed, and took it through a class A landing safety test.

I think... I think this lady might finally be ready for production and use in the field. Oh, and it'll go to 40k before flameout, which is just monstrous

[Wanderfound]

Kerbodyne Liftjet.The reusable SRB.

Flight test at http://s1378.photobucket.com/user/craigmotbey/Kerbal/Beta/Kerbodyne%20Showroom/Liftjet/story

Alternate format at http://s1378.photobucket.com/user/craigmotbey/slideshow/Kerbal/Beta/Kerbodyne%20Showroom/Liftjet

Craft file at https://www.dropbox.com/s/p0gk4e4u4crmv67/Kerbodyne%20Liftjet.craft?dl=0

Edited March 6, 2015 by Wanderfound